1. Field of the Invention
The present invention relates to a wiper assembly for wiping a windshield of a motor vehicle, and more particularly to such an assembly that has multiple blades for removing different substances from the windshield.
2. Description of the Related Art
The motor vehicles, such as automobiles, motorcycles and aircraft, commonly have a mechanism for wiping rain water and debris from the windshield to enable the driver to see the road ahead. Typically there is a pair arms that that move in an oscillating manner over the windshield when driven by a motor. A separate windshield wiper blade assembly carried at an end of each arm moves in an arcuate path across the windshield.
The conventional automobile windshield wiper blade assembly is sufficient for wiping water and water soluble materials from the windshield, but is ineffective for removing substances which are not water soluble, such as bugs, secretions from trees, road dirt, grease and oil.
Heretofore, attempts have been made to provide a windshield wiper blade assembly for cleaning non-water soluble materials as well as water from the windshield. One type of previous device, shown in U.S. Pat. No. 4,567,621, used a single composite blade in which a scrubbing strip was sandwiched between two conventional wiper blades. Gaps were eliminated between the three blade components so that dirt removed from the windshield could not accumulate therein.
Windshield wiper assemblies with multiple blades also have been proposed. U.S. Pat. No. 5,168,595 discloses a combination of three different types of blades with one of them being tilted into an operating position by an electrically operated actuator. This mechanism required that the driver of the vehicle operate a switch to select the particular blade to use. U.S. Pat. No. 4,745,653 shows three blades arranged in a “Y” configuration with a sponge located between two of the blades. The driver of the vehicle manually rotated the blade assembly about the center axis of the “Y” to select which ones of the blades and the sponge engaged the windshield. The vehicle driver had be outside the car to position the blade assembly.